Over the years, several methods of administering biologically-effective materials to mammals have been proposed. Problems arise when the desired medicinal agent is insoluble in aqueous fluids. Alkaloids are often especially difficult to solubilize.
Camptothecin is a water-insoluble cytotoxic alkaloid produced by Camptotheca accuminata trees indigenous to China and Nothapodytes foetida trees indigenous to India. Camptothecin and related analogs are known to be potential anticancer agents and have demonstrated therapeutic activity in vitro and in vivo.
Camptothecin and analogs are known as DNA topoisomerase I inhibitors. For example, one of camptothecin analogs is Irinotecan (CPT-11, Camptosar®) which is also a DNA topoisomerase I inhibitor and has also showed anticancer activity. 7-ethyl-10-hydroxycampothecin is an active metabolite of CPT-11.